Metal-working device



Feb. 16 1926.

' 1,573,503 F. 0. RIFNER I METAL WORKING DEVICE Filed May 25 1925 2 Sheets-Sheet 1 pressure plate in this sl'ie'et-metal-engaging .30 position during the draw ng operation.

Patented Feb. 16, 1926.

UNITED STATES f' I I 1,573,503

FRANK 1). RIFNER, or DAYTON, OHIO.

METAL-WORKING DEVICE.

Application filed May 25, 1925. Serial No. 32,600.

To all whom it may'concem: 4

Be it known that I, FRANK D. RIFNER,

a citizen of the United States of America,

residing at Dayton, county of Montgomery, and State of Ohio,have invented certain new and useful Improvements in Metal-Working Devices, of which the following is a full-,

clear, and exact description. Y

This invention relatesto improvements in metal, working devices and particularly to such devices used for drawing sheet metal.

It is among the objects of the present invention to provide a device, sturdy in structure and simple in design, which will eliminate crinkles in the sheet metal stock as it is drawn, thereby'producing an even and smooth surface'on the object produced. I

Such a machine has been shown in the drawings of the present application as including male and female die members; a v 32. These cams are parallel with the male pressure plateadapted .to move by gravity, into engagement 'with'the sheet metal on the female die member, upon approaching movement of the male die member toward the slieet metal; and means, includingpivoted locking levers'and' a cam for operating said levers, for'securely locking the Further objects and advantages of the present invention will be apparent from the followingdescription, reference being had to the acoompanying drawings, wherein a preferred form of the presentinventior is clearlyshown.

In the drawings: Fig.1 isa perspective view of'the device.

. Certain parts have been broken away to save space on the drawings.

Fig- 2 is a fragmentary front Vl8W Sl1OW-' mg the wedge-shaped cam in the extreme down position, between the can' ming le-r' I member at- 4l4; of Fig. 3, andshows thev camming levers adjusting device... 7 Fig. 5 shows the ClGVlCQfidltflCllGd on'a punch press.

Fig. 6 is a fragmentary side view of the device as shown n Fig. 2. Y

Referring to the drawings, and particu-' larly to Fig. '5, the numeral 20 designates the base plate of the punch press; 21 the vertical standards which support the crankshaft 22, driven by means, of a pulley 23. A crank arm 24 connects the crankshaft 22 with a drop head 25 slidably supported on the vertical standards 21. Y

The sheet-metal-drawing device comprises a male die member 26, carried-by or'formed integral with aplunger block, is adapted to be inserted in the drop head 25 of the punch press, for securing the male die member to said drop head. On one side of the plunger 7 block 27 there is secured a cam element'29 by means of stud 30,. while on the'direct opposite side of'said plunger block, asiniig lar cam 31 is supported by means of stud die member 26, said cams having opposite lel fora predetermined distance, then com verging to form a wedge-shapedoperating 7 portion, as shown at35, for purposesto be described.

The female'die member designated by the numeral 36, includes oppositely disposed feet 37 and 38, said-feet being each provided with a slot for receiving studs 39 and lO, for the purpose of securing the female diemember to the base plate 20 of the punch press. Fhe female die may also be secured in a block, in which case the block would comprise the elements 36, having feet 37 and 38, the fe-'- male die member being secured in the block in any suitable manner. a Interposed between theplunge'r block '27 and the female die member 36, is a pressure plateetl, having a central apertu're through which the male die member 26 is adapted to pass. 011 each side of the male die mem ber 26 there is provided comparatively long studs 42, one end of these studs being screwed into the plunger block 27. -Both studs pass through holes formed in the pressure plate 41 and the free ends-0f the studs are provided with' he ad portions. -Thisis clearlyillustrated'in Fig. 6. From thisit can be seen that when the'plunger'block'27 movesupwardly away from the female die member, the studs 12 will move through the holes in the pressure plate ll until the heads of said studs engage with the bottom surface of the pressure plate, at which time said pressure plate will be moved upwardly with the plunger block 27, thus moving said pres sure plate away from the female die member. Upon return movement of the plunger block 27 toward the female die member 36, the pressure plate 41 will move downwardly with the studs 42, until said plate with the sheet metal positioned on the female die 36, at which time continued movement of the plunger block downwardly will tend to move the studs through the plate t1, the heads of the studs 42 entering the pesages provided in the female die member for that purpose.

The pressure plate ll is provided on its one side with a recess, the upper edges of this recess being beveled off as at d6, for purposes to be described. On the direct opposite side of the pressure plate ll, a similar recess is formed;

A pair of levers l? and 18 are pivotally supported on each one of the opposite sides of the female die membe' 36. They are held in position on the plate by means of nuts 49 and 50. These levers, when in their inoperative position, are drawn together by means of a spring 51 which is anchored on studs formed integral with nuts and The nut 52 supports a roller adjacent the free end of the lever l7, while the nut supports the roller 55 adjacent the free end of the lever 48. The lev rs on the opposite side of the female die member 86 are similarly provided. Each lever is provi led with a sloping surface 56, on its outer edge and so positioned that said sloping edge 56 may engage with the beveled edge 46 of the respective recess formed in pressure plate all under conditions which will be explained hereinafter.

In order to adjust the relative position of the sloping surfaces 56 of the various levers to the position of the pressure plate 41, when in engagement with the sheet metal, an adjustable support is provided for the directly opposite levers of each pair. This adjustable support is clearly illustrated in the Fig. 4, and comprises a central bearing portion 60, adapted to fit in a transverse passage formed in the female die member 36. On one side of the die member 36 the supporting member is provided with a bearing portion 61, eccentric to and larger than the portion 60. The lever supported on the female die member 36 directly opposite the die member 48 and which may be designated 48 is carried by the portion 61 and held in position between the female die member and a head 62 formed integral with the portion 61. On the opposite side of the female die member and extending beyond the surface thereof, is a portion 63 eccentric to but smaller in diameter than the portion of the supporting device. This portion 68 has a flat surface 64 formed thereon, which prevents rotation of the collar 65 fitting on this portion 63. The collar 65 is of equal outside diameter to the portion 61 and acts as a bearing for the lever 48. The nut 50 is screwed onto the screw-threaded portion 66 formed on the portion 63; thus, said. lever 48 is held in position between the female die member 36 and the nut- 50. lVhen adjust-- ments of the levers are desired, the nut 50 is loosened and the head portion 62 is retated. Thereby rotation of the portion 60 and the die 36 will either throw the portions 61 and 63 upwardly or downwardly, depending upon the direction of eccentricity, thereby moving the levers upwar lly or downwardly, respectively, and consequently reducing or increasing the space between the beveled surface 56 and the surface of the female die member 36.

The operation of the device is as follows:

hen the male die member 26 is in the position as shown in Fig. 3, the cam 29 is just moving from between the rollers 54 and carried on levers 47 and 18. This is also true of the cam on the opposite side of the plunger block-27. Continued movement upwardlyof the male die member will permit the spring 51 to move the rollers 54 and 55 into engagement, thereby moving the sloping surfaces away from the edges of the recess 45 so that when the'heads or studs 42 engage with the pressure plate -11, moving it upwardly, the levers 47 and 48 will clear the edges of the recess in the pressure plate. A piece of sheet metal is then inserted in the die, lying directly on the female die member 36. Now, when the male die member moves downwardly, the pressure plate (l1 will move by gravity with the studs 42 until said plate comes to rest on the sheet metal lying on top of the female die member. At this time the cam element 29 will have its wedgeshaped portion 35 entering between the rollers 5i and 5? and tending to move them away from each other, so that the sloping surfaces 56 of each of the rollers will be moved outwardly to engagewith its respective beveled edge of the recess 45, in which the rollers are now positioned. The adjusting element on the levers having been set for the thickness of the metal to be used in the die, the rollers when engaging with the parallel surfaces 38 and 3st of the cam 26, will hold the levers l? and 18 in such a position where their respective sloping surfaces 56 will lock with the beveled edges 46 and the recess, thereby loekingthe pressure plate 41 in the position on the sheet metal. From this it will be seen that the sheet metal top of the plate.

lies between two non-yielding rigid walls formed by the upper surface of the female die member 36 and the lower surface of the pressure plate 41.

During the entire drawing operation the parallel surfaces 33 and 3d of the cam 29 will maintain the levers 47 and 48 in a constant position.v I

It may clearly be seen that when thinner metal is desired to be drawn, the adjusting element shown in Fig. t may be operated to move the levers 47 and a8 and the correfemale die member. j

Previous practice provided springs, rubber or air pressure on a pressure plate for holding the sheet metal against the female ;die member durng operations, and in these devices as the plunger moved downwardly, the pressure on the pressure plate was increased. This is ent'rely eliminated .in the present structure. Here the pressure plate is permitted to drop by gravity onto the metal, the only pressure on the metal being the weight of the pressure plate. As soon as this pressure plate comes to rest on the metal, locking devices are brought into effeet for locking this pressure plate in this position. No extra pressure is exerted on the pressure plate by th s locking operation. In the old devices, the provision of springs, rubber orair on the pressure plate, provided a. yield able pressure on the pressure plate, so that it was possible to move the pressure plate away from the female die member, due to this yielding pressure on However, in the present structure the pressure plate is held nonyieldingly in pos'tion on the sheetinetal, still not exerting any undue pressureQon the metal while it is being drawn. I

In a portion of the description of the operation, reference is made to the pair of levers on one side of the female die member only. It will, of course, be understood that the levers on the oppos'te side of the die member are correspondingly operated and correspondingly lock the opposite'side of the pressure plate in position.

.Vhile the form of embodiment of the invention as herein disclosed, constitutes a preferred form it is to be understood that other forms might be adopted, all coming' within the cope of the claims which follow. 7

V] hat is claimed is as follows:

1. A device fordrawingsheet metal comprising, in combination, a die including male and female members; a pressure plate adapted to be moved into engagement with the metal on the female die member; and a 1 pressure-plate locking means provided on each one of two opposite sides of the'die, each of said locking means including a pair of locking levers adjustably secured to the female die member, and wedges rigidly mounted on the male die member and adapted to be inserted between their respec- .t ve pair of looking levers whereby said levers will concurrently be moved in opposite directions and into locking engagement with the pressure plate.

2. A device for drawing sheet metal comprising, in combination, a die including maleand female members; a pressure plate adapted to be moved into engagement with the metal on the female die member; .and a pressure-plate locking means provided on each one of two opposite sides of the die, eachof said locking means including a pair of locking levers adjustably secured to the female die member for each pair of levers,

and a singlc'wedge-shaped member having a variable dwell and a constant dwell and adapted to beinserted between its respective pair of locking levers whereby said levers are concurrently moved apart and in to proper engagement with the pressure plate and then constantly held in this pressure-plate-engaging position.

3. A device for drawing sheet metal comproper prising, in combination,a die including male and female members; a pressure plate adapted to be moved into engagement with the metal on the female die member; and a pressure-plate locking means provided on each one of two opposite sides of the die,

each of said locking means including a pair of locking levers, each lever having its one end'pivoted to the female dle memberand provided with a roller at its other end, and

and then constantly hold said levers in this proper position.

4. A device for drawing sheet metal, comprising in combination, male and female die members; a pressure plate adapted to be moved into engagement with the sheet metal on the female d'e member; a pair of looking levers providedon each one of the two opposite sides of the female die member; and common means for V ad ustably and pivota-lly supporting the directly opposite levers of each pair of levers on the female die member, thereby permitting simultaneous adjustment ofboth said levers.

' 5. A device for drawing sheet metal, compris ng in combination, male and female die each carrying the two directly-opposite members; a pressure plate adapted to be levers of each pair of levers, aid means he 10 moved into engagement with the sheet metal ing adapted to simultaneously adjust their on the female die member; a pair of locking respective two levers of each pair of levers. levers pivotally supported on each one of In testimony whereof I hereto afiix my the two opposite sides of the female die signature.

member; and eccentric adjusting means ex tending through the female die member, FRANK D. RIFNER. 

